Ventilated electromagnetic structure



June 6, 1933. v. G. APPLE 1,913,138

VENT ILATED ELEG TROMAGNET IC STRUCTURE Filed July 10, 1930 2Sheets-Sheet 1 IN VEN TOR June 6, 1933. v. G. APPLE 1,913,138

VENTILATED ELECTROMAGNETIC STRUCTURE Filed July 10, 1950 2 Sheets-Sheet2 Patented June 6, 1933 UNETED STATES PATENT OFFICE VINCENT G. APPLE, OFDAYTON, OHIO; HERBERT F. APPLE, EDWARD DI. APPLE, AND GOURIAEY DARROCHEXECUTORS F SAID VINCENT G. APPLE, DECEASED VENTILATED ELECTROMAGNETICSTRUCTURE Application filed July 10,

This invention relates to electromagnetic structures wherein the corelaminae are spaced apart at intervals for ventilation.

The object of the invention is to provide a structure wherein the coreis composed of spaced apart groups of laminae, and where the entirewinding is imbeddcd and encased in a solid mass of insulation.

I attain this object by the structure hereinafter described, referencebeing had to the drawings wherein- Fig. 1 is a fragmentary end view ofan armature core selected to illustrate my invention.

Fig. 2 shows a fragment of a special laminae used at intervals in mycore.

Fig. 3 is a fragmentary cross section taken at S 3 of Fig. 1.

Fig. 4 shows the section Fig. 3 but with the bundles of wires composingthe winding in the core slots.

Fig. 5 is an axial section through a mold in which the armature isinsulated, the left side being taken through 5-5 of Fig. 6 and rightside through 55 of Fig. 6.

Fig. 6 is a fragmentary section. taken at 6-6 of Fig. 5.

Fig. 7 is an axial section through the completed armature, the left sidetaken at 77 and the right side at 7-7 of Fig. 8.

Figs. 8 and 9 are fragmentary sections taken at 8-8 and 9-9 respectivelyof Fig. 7

Similar numerals refer to similar parts throughout the several views.

In dynamo electric machine elements of large size it is common practiceto provide a vcntila ting means to assist in cooling the ele ment byleaving out groups of several laminze each throughout the length of thecore. 40 Such a structure comprises in effect a number of short coresections in axial alignment with some sort of spacers between theseveral sections to keep them apart.

Such large size elements are usually bar wound, and when the barscomposing the 1930. Serial No. 467,008.

winding are laid in the core slots they necessarily cross the openspaces between the several sections of the core. In a revolving elementconstructed in this fashion the parts of thewinding bars which crossthese open spaces have the same effect as the blades of a centrifugalblower to move a cooling medium outwardly through the spaces between thecore sections.

But when this same core is wound with a large number of relatively finewires in each core slot the problem is more difficult, since the coilsof wire which fill a slot must cross the open spaces between the coresections and some provision is preferably made to keep the wires of thecoils together and to insulate them. In the present invention this isaccomplished by molding an integral mass of insulating material toextend through, between and completely around the several turns of thewinding and about the winding heads at the ends of the core, the partsof the mass at the ends of the core being joined by integral struts ofinsulation extending.

through the slots and by an integral cylinder of insulating lining theinner diameter of the core the insulation mass at the same timeproviding permanent spacing means to hold the several core sectionsspaced apart. The struts which extend through the core slots completelysurround and enclose the coils of wires therein, the wires acting asreinforcement for the struts. The coils of wire are thus not onlyenclosed where they pass through the slots but also where they bridgethe spaces between the core sections.

The laminated core 10, Fig. 1 has winding slots 11 separated by teeth12. There is a large central opening 13. The coreis composed mostly oflaminae of conventional design but at intervals a special lamina 14L,Fig. 2 having temporary spacing lugs 16 is interposed. The lugs 16 areturned up from part of the metal ordinarily removed when the slots 11are punched. Fig. 3 is a fragmentary section of a core 10 showing howthe lugs 16 keep the several core sections spaced apart.

Fig. ii: shows the same fragment as is shown in 3 but with the coils 17of wire composing the winding in the slots. Before the coils are laid inthe slots the slots are lined, preferably with a coarse loosely wovenfal ric S which holds the coils away from the sides oi? the slots untilthe permanent insulation in fluid form may be forced into the space,after which the fabric serves merely as reinforcement for the permanentinsulation.

Fig. 5 shows the core 10 with its coils 17 and suitable collector rings19 and 21 located within the winding head 22 in the insulating mold 23.The coils are attached to the collector rings 19 and 21 at 2i and 26respectively.

The mold 23 comprises a one piece base and center plug 27 which hasshoulders 28 and 29 uponwhich rings 19 and 21 rest. The cylinder 31 isconcentrically supported on the base at The opening through cylinder illis of two diameters. At it its the core sections, while the smalleropening 34 pr0- vides a shoulder 36 upon which the core may rest.

A plurality of side pulls 37 extend through i the wall of cylinder illin circular rows.

There are as many rows there. are open spaces between the core sectionsand as many pulls in a row as there are teeth in the core. Pulls 37 havetapered sides and when in place occupy the spaces between coils 17 andextend radially inward until th y touch the center plug 27. Notches 38in the sides of the pulls provide means to engage them to withdraw themafter insulation of the armature has been eflected.

it stock ring 39 fits over the upper end of cylinder 31. The openingthrough the stool: ring is somewhat smaller than tl e core 10. the endresting on the core at 41 to hold it in place. A hollow plunger 42- hasan outer diameter slidably fitted to the stool; ring and an innerdiameter slidably fitted over the center plug :27. The lower end of theplunger 42 is shaped out to make room for the wind head Mold Bis shownclosed about the armature as it appears before any of the insulation hasbeen placed. and it will be seen that there is continuity between thespace A- around the upper winding head the space l6 at the upper end ofthe core. the spaces 47 between the center plug 2? and the core 10, thespaces it? left between adjacent pulls 3'? and between adjacent coresections, the space 4-9 at the lower end of the core, and the space 51around the lower wind j head and the rings 19 and 21, so that insulationplaced in the mold at the upper end of the core may be fluxed and forceddownwardly into all the space in the mold not occupied by solidimpenetrable material.

To operate the mold shown in Fig. 5 the mold and its contents areheated, the plunger 42 removed, a proper quantity of insulation,preferably one of the commercial thermoplastic compounds, placed on thetop of the core, and the plunger put in the mold on top of the compound.When the stored heat of the mold fluxes the compound the plunger ispressed downwardly to the position shown, the insulation allowed toharden after which the pulls 37 are withdrawn to leave the open ings 52,and the armature is removed from the mold.

F ig. 7 is an axial section through the completed armature. the leftside of the view being taken through one of the coil sides where itextends through a core slot as at 77 of Fig. 8 and the right side of theView being talfen through one of the core teeth and be tween two coilsides as at 77 of Fig. 8, thus cutting through a row of the openings 52.

From a consideration of Fig. 7 and the fragmentary section Figs. 8 and 9it will be seen that there is one single continuous mass of insulation53 extending through and about the coil sides in the slots, and throughand about the winding heads, forming the perforated cylinder which hasthe integral wedge shaped spokes extending radially between the coresections, these spokes serving also as spacers for the core sections andas coverings for the otherwise unsupported parts 56 of the coil sideswhich bridge the gaps between the several core sections.

Flanges 57 are placed in the ends of the armature to support itconcentrically on the shaft A nut 59 draws the two flanges tog'cther. Akey (31 provides driving relations between the shaft 58 and the oneflange 57, while pins 62 provide driving relation be tween the flangeand the armature. Openings 63 through the flanges admit air or othercooling medium into the space between the flanges.

The advantages of the structure are obvious. for while a large number ofopenings er;- tend outwardly through the core and windings wherebyrotation of the armature gives adequate ventilation the entire windingat the same time imb-cdded and cncascd in an impervious insulation masswhereby the armature is adapted to situations where the air available acooling incdium contains a large percentage of dust, moisture, acidfumes or other substances destruct'vc to the ordinary exposed orinadequately insulated windings. The armature shown of courseparticularly adapted to be used with a stator element which is similarlytreated, but it may he used with any stator which arrangedv as not toobstruct the outward passage of the cooling medium through the ducts.The

principle of my invention is of course also applicable to any stationaryelectromagnetic structureby providing means to move the cooling mediumthrough the ventilating openings.

WVhile I have indicated a preferred kindot insulation and a preferredprocedure for applying it, any kind of insulation which can be made topenetrate the winding and form an impervious coating thereabout may beapplied in the manner indicated or it may be applied by any other seriesof steps suitable to the nature of the insulation used, and when soapplied will be considered as coming within the spirit of the invention,to specifically define which I claim,

1. The combination in an electromagnetic structure of a core comprisingspaced apart sections, a Winding on said core, and a single mass ofinsulation penetrating and completely covering the entire winding andfilling the space between the core sections, there being a plurality ofventilating openings through the mass between the said core sections.

2. The combination in an electromagnetic structure of a core comprisingspaced apart sections, a winding on said core, and a single mass ofinsulation penetrating and completely covering the entire windin g an dfilling the space between the core sections, said mass having aplurality of ventilating openings ex tending therethrough between thecoils where they extend cross the space between the core sections.

3. The combination in a dynamo electric machine element of a slottedcore with a central opening, said core being in spaced apart sections,and an integral. mass of insulation extending through the slots of saidcore and filling the space between the core sections, the part of themass between the core sections having a plurality of ventilatingopenings extending through the mass from said central opening outwardly.

4c. The combination in a dynamo electric machine element of a corehaving a central opening, said core being in spaced apart sections, anda single mass of insulation forming a lining for said central openingwith. spokes extending outwardly into the space between the saidsections.

5. The combination in a dynamo electric machine element of a corecomposed of laminae having winding slots and a central opening, saidlaminae being arranged in groups to compose spaced apart core sections,coils in said slots extending across the spaces between said coresections and forming coil heads at the outer ends of the core, and asingle mass of insulation penetrating and surrounding the winding heads,lining the central opening of the core and extending outwardly betweenthe core sections and lengthwise through the core slots, said masshaving a plurality of radial ventilating openings extending between thecoils where they extend across the space between the core sectionsinwardly through said lining.

6. The combination. in a dynamo electric machine element having acentral opening, of core comprising a plurality of slotted laminaearranged in spaced apart core sections, coils comprising a plurality ofinsulated wires in the slots of said core extending acrosstthe spacesbetween said core sections, and a single piece of insulation comprisinga cylindrical lining 'for the central opening and. a plurality of radialspokes extending from said lining between the core sections, the coil.sides where they extend between core sections being imbeddcd andcompletely enclosed in the outer ends of said spokes.

7. The combination in a dynamo electric machine element having a centralopening, of a core comprising a plurality of slotted laminae arranged inspaced apart core sections, coils comprising a plurality of insulatedwires in the slots of said core extending across the spaces between saidcore sections and an integral mass of insulation penetrating andcompletely surrounding the winding and extending within and between thecore sections, said mass having a plurality of radial ventilatingopenings extending from the outer diameter of the element into thecentral opening, said ventilating openings being arranged in circularrows, one row in each space between core sections and the severalopenings of each row being between adjacent coil sides where they extendacross the open spaces between core sections.

8. The method of making a ventilated electro-magnetic structure whichconsists of assembling a plurality of laminae of magnetizable materialin groups, spacing apart the groups to form a core, placing a winding onthe core, placing a spaced apart row of pulls bet-ween each. group,pressure molding a mass of insulation into and about the coils, aboutthe core, and between the pulls in the spaced apart core sections,hardening the insulation, then removing the pulls to term a spaced apartrow of ventilating ducts between each said pair of spaced apart coresections.

9. The method of making a ventilated dynamo electric machine element,which consists of building up a magnetizable core in spaced apartsections, from annular laminae having circular rows of windingapertures, placing coils on said core with the coil sides in saidapertures and extending across the spaces between the sections, placinga plurality oi wedge shaped pulls in circular rows between the spacedapart sections, each pull being between and spaced slightly away fromadjacent coil sides where they cross the spaces between said sections,molding a mass of insulation through and about the core, the coils andthe pulls, hardening the insulation, then removing the pulls.

10. A dynamo electric machine element comprising a core, a winding onsaid core hav- 5 ing an annular winding head extending axial- 1y beyondone end of said core, two collector rings concentrically located withinsaid annular winding head spaced apart from said head, from each otherand from the core, 10 ends of said winding being electrically joined oneend to each collector ring, and an integral mass of insulation moldedthrough and about said core, said winding head and said collector rings,said insulation mass constituting the sole support for said collectorrings. In testimony whereof I aflix my signature.

VINCENT G. APPLE.

